This chapter presents the kinematics of waves. It describes wave motions without reference to the particular physical nature of the wave. Sound waves, light waves, and water waves are quite different physically. However, each displays certain kinematic features that are identical or very similar. A wave is a disturbance that travels at a definite speed. The chapter illustrates the principle of superposition for waves on a string. The superposition of waves can result in interference. At points where superposition causes the waves to oppose one another, it is called destructive interference. At points where superposition causes the waves to rein-force one another, it is called constructive interference. Relative motion between a source of waves and an observer of waves results in the Doppler effect. The chapter discusses the kinematic aspects of waves, particularly sinusoidal wave.